Method of using molybdenum carbide catalyst

Abstract

A molybdenum carbide compound is formed by reacting a molybdate with a mixture of hydrogen and carbon monoxide. By heating the molybdate powder from a temperature below 300° C. to maximum temperature 850° C., a controlled reaction can be conducted wherein molybdenum carbide is formed. A high surface area, nanograin, metastable molybdenum carbide can be formed when the reaction temperature is below 750° C. The metastable molybdenum carbide is particularly suitable for use as a catalyst for the methane dry reforming reaction and the water gas shift reaction.

We claim:  
     
         1 . The method of forming hydrogen from a gas mixture of methane and carbon dioxide comprising contacting gas said mixture with a catalyst comprising molybdenum carbide having a surface area of at least 35 m 2 /g.  
     
     
         2 . The method claimed in  claim 1  wherein said catalyst has a surface area of at least about 50 m 2 /g.  
     
     
         3 . The method claimed in  claim 1  wherein said gas mixture has a ratio of carbon dioxide to methane of from about 1 to 10 to 10 to 1 by volume.  
     
     
         4 . The method claimed in  claim 3  wherein said reaction is conducted at a temperature of about 700° to about 900° C.  
     
     
         5 . The method of conducting a water gas shift reaction comprising contacting a gas comprising a mixture of hydrogen, carbon monoxide and water vapor at a temperature of about 200° to 550° C. in contact with a catalyst said catalyst comprising molybdenum carbide.  
     
     
         6 . The method claimed in  claim 5  wherein said molybdenum carbide has a surface area greater than 35 m 2 /g.  
     
     
         7 . A method of utilizing a molybdenum carbide catalyst in a reaction vessel having a controlled atmosphere comprising: 
 passivating said molybdenum carbide catalyst to form oxides on surfaces of said molybdenum carbide catalyst;    introducing said molybdenum carbide catalyst into a reaction vessel;    activating said molybdenum carbide catalyst by passing a carburizing gas in contact with said catalyst at an elevated temperature effective to activate said catalyst.    
     
     
         8 . The method claimed in  claim 7  further comprising passing a carbon containing gas in contact with said catalyst to form a reaction whereby a said catalyst is at least partially deactivated; further comprising reactivating said catalyst by introducing a carburizing gas into said reaction vessel in contact with said catalyst at a temperature effect to reactivate said catalyst.  
     
     
         9 . A method of forming a high surface area Mo 2 C comprising soaking a molybdenum compound selected from the group consisting of molybdates and oxide in a H/CO gas at 300°-400° C. for 1-5 hours; 
 subsequently soaking said molybdenum compound in a H/CH 4  mixture for 3-5 hours at a temperature of 550°-850° C.